1. Field of the Invention
The invention relates to a supporting device for a liquid crystal display, especially to a supporting device that is simple in production and assembly, and able to provide a large adjusting angle for the liquid crystal display attached thereto.
2. Description of Related Art
Liquid crystal displays are widely used in public places such as airports, railway stations, stores, and public squares, etc. They are usually fixed to a frame by a supporting device. Shown in FIGS. 5, 6, 7 and 8 is such a supporting device. The device includes a clip (20) that is able to be secured to a frame, a base (21) formed on the clip (20), an adjustment means, an arm (30), and a positioning means formed on a top of the arm (30). A cylinder means is contained in the arm (30). The cylinder means has a shaft (301) received in a shaft tube (300). The arm (30) and the shaft (301) are pivotally connected to the adjustment means. A free end of the shaft tube (300) is pivotally linked to the arm (30). In order to bear liquid crystal displays of different weights, an angle of the cylinder means with respect to the arm (30) must be adjustable. Adjustment is released via the adjustment means. The adjustment means has an outer seat (40) having a slot (41), an inner seat (45) having a pair of legs, a pin (42), a long bolt (43), and, a slidable pin (44). A leg slot (451) is defined in each leg of the inner seat (45). In assembly, the inner seat (45) is first put into the outer seat (40) and secured by bolts. Then the pin (42) is installed in the slot (41) with two ends thereof being inserted into two openings defined in a pair of ears. Then the slidable pin (44) is put between the two legs with two ends (441) thereof being placed and slidable in the leg slots (451). The long bolt (43) is threaded into a thread hole traversely defined in the pin (42) and then into another thread hole traversely defined in the slidable pin (44). A shaft cover (302) has an upper portion which is able to threadedly engage with a free end of the shaft (301), and further has a lower portion which is able to ride on the slidable pin (44). To adjust the angle of the cylinder means with respect to the arm (30), a user can rotate the long bolt (43). Then the slidable pin (44) will move along the leg slots (451) and then the angle is able to be adjusted.
The positioning means includes a lower connecter (31) pivotally linked to the top of the arm (30) and an upper connecter (32) pivotally linked to the lower connecter (31). The lower connecter (31) is able to rotate left and right about the arm (30) and the upper connecter (32) is able to rotate forward and backward about the lower connecter (31). The upper connecter (32) has a top plate on which a bolt (33) is formed. The bolt (33) can go through a central opening defined in a fixing plate (34) and then threadedly engage with a nut (35). A portion of the bolt (33) that protrudes from the nut (35) is forged to form a rivet nut head and then the fixing plate is connected to the upper connecter (32). The fixing plate (34) is then able to be secured to a liquid crystal display.
From above description, it is to be seen that the conventional supporting device has the following drawbacks:
1. It has too many constituent members, some of which have a very complex shape that is difficult to manufacture;
2. Its assembly has too many steps, which will bring much inconvenience;
3. The fixing plate (34) is able to rotate with respect to the upper connecter (32) about the bolt (33);
4. The upper connecter (32) has only one ear sandwiched between two ears of the lower connecter (31) and therefore cannot provide enough support for the upper connecter (32). In actual use, the single ear often deforms due to excessive stress thereon;
5. as shown in FIG. 8, if the arm (30) is needed to be at a large angle with respect to the base (21), the shaft cover (302) will finally meet the long bolt (43). In the conventional supporting device, the angle that the arm (30) is able to rotate with respect to the base (21) is less than 90 degrees which is insufficient in actual use.
The main object of the invention is to provide a supporting device for liquid crystal display that is simple in structure, easy to assemble, and able to provide a secure support for a display installed thereto.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.